Abstract: A stackable weight plate for an exercise machine weight stack has a front edge, a rear edge, opposite side edges, an upper face, a lower face, and an aperture extending between the upper and lower face for receiving a weight stack selector stem. The front and rear edges having a matching arcuate curvature with one edge being convex and the other edge being concave, and the side edges are tapered at an angle from the front edge to the rear edge.

Abstract: A stackable weight plate for an exercise machine weight stack has a front edge, a rear edge, opposite side edges, an upper face, a lower face, and an aperture extending between the upper and lower face for receiving a weight stack selector stem. The front and rear edges having a matching arcuate curvature with one edge being convex and the other edge being concave, and the side edges are tapered at an angle from the front edge to the rear edge.

Abstract: A weight lifting exercise machine has an adjustable seat supporting arm assembly to permit the machine to be used by handicapped users in a wheelchair as well as non-handicapped users. In a first condition, an extendible support arm is secured in a seat-supporting position projecting forwardly from an upright frame member carrying a back rest so as to support a seat pad in an appropriate position relative to the back rest for use by a seated, non-handicapped user. In a second condition, the seat pad is removed from the arm and the arm is retracted rearwardly to provide a space for positioning a wheelchair adjacent the upright member with a user in an equivalent position to a non-handicapped user for access to the exercise equipment.